This vid gives a short demonstration of the quality of sound driving this thing straight from 2 x 9V batteries! To the left of the synth, you can see wires attached to the two batteries. For me- very interesting as the synth stay in tune very well here. Also tech folks please note- there are neither smoothing capacitiors or regulators of any kind used here!The batteries at this point were sitting at around the 8.5V mark!